The present invention relates to a rotary bearing device, an joint device, a wiring device for joint mechanism and a robot, and is preferably applicable, for example, to a gressorial robot.
There has been developed a small gressorial robot which has a form like that of man or an animal and can walk with two or four walking leg members. Such a wiring device as shown in FIGS. 7 and 8, for example, is adopted in an joint mechanism of a leg member of such a kind of gressorial robot.
That is a conventional joint mechanism 51 shown in FIGS. 8 and 9 comprises a leg member 53 which is coupled with a leg attaching member 52 so that the leg member 53 is rotatable around two perpendicularly intersecting rotating shafts 54 and 55 disposed at a center of an joint. In this joint mechanism, the two rotating shafts 54 and 55 are rotatably attached to the leg attaching member 52 and the leg member 53 by way of a pair of radial bearings 56 and 57 respectively which are ball bearings or the like, and partial gears 58 and 59 are formed integrally with outer circumferences of intermediate portions of the rotating shafts 54 and 55. A shaft fitting member 60 formed integrally with a tooth-lack portion which is a portion of an outer circumference of the partial gear 59 on a side of the leg member 53 is detachably fitted over a tip 54a of the rotating shaft 54 on a side of the leg attaching member 52 in an axial direction, and the shaft fitting member 60 and the tip 54a are detachably coupled at their centers with a screw 61 which runs in a direction perpendicular to the axial direction. The leg member 53 can be rotatingly driven relative to the leg attaching member 52 around the two rotating shafts 54 and 55 within a definite angle by rotatingly driving the partial gears 58 and 59 of the two rotating shafts 54 and 55 independently with a driving gear 63 of an actuator 62 such as a geared motor or the like attached to the leg attaching member 52 and the leg member 53 respectively (see FIG. 11).
At a stage to electrically connect a pair of control circuits (not shown) which are built in the leg attaching member 52 and the leg member 53 respectively with a cable 64 used as a wiring material, a wiring device for the joint mechanism 51 shown in FIG. 8 allows the cable 64 to be laid so that it is exposed outside the joint mechanism 51 by detachably connecting a pair of connectors 65 and 66 which are preliminarily connected to both ends of the cable 64 to the pair of control circuits.
On the other hand, a wiring device for the joint mechanism 51 shown in FIGS. 9 through 11 uses hollow shafts as the two rotating shafts 54 and 55, and allows the cable 64 to be inserted through and along center slots 67 and 68 of the rotating shafts 54 and 55. Since the cable 64 is inserted through the center slots 67 and 68 of the rotating shafts 54 and 55 in this case, the screw 61 cannot run through the center of the rotating shaft 54 to attach the shaft fitting member 60 to the tip 54a of the rotating shaft 54 and it is necessary to tighten the shaft fitting member 60 to both sides of the rotating shaft 54 using a pair of screws 61.
The wiring device shown in FIG. 8 allows an angle sensor 68 or the like to be attached coaxially with a playing end 54b of the rotating shaft 54 (and the rotating shaft 55) to configure the joint mechanism 51 as a whole compact since the cable 64 is not inserted through the rotating shafts 54 and 55, whereas the cable 64 which is exposed outside the joint mechanism 51 degrades an aesthetic appearance. The cable 64 must have a large margin in its length in order to reserve a large movable range for the leg member 53 and therefore poses a problem that the cable 64 is liable to twist around another part during a movement of the leg member 53 and is easily broken.
Furthermore, the wiring device shown in FIGS. 9 through 11 does not allow the cable 64 to be exposed outside the joint mechanism 51 since the cable 64 is inserted through and along the center slots 67 and 68 of the rotating shafts 54 and 55, whereas the wiring device makes it impossible to attach the angle sensor or the like coaxially to the end 54b of the rotating shaft 54 (and the rotating shaft 55). Since the connectors 65 and 66 have an outside diameter which is generally larger than that of the cable 64, the connectors 65 and 66 cannot pass through the center slots 67 and 68 when a small joint mechanism 51 must use the rotating shafts 54 and 55 which have so small a diameter as not to permit forming the center slots 67 and 68 larger than the outside diameter of the connectors 65 and 66, whereby the wiring device cannot use the cable 64 which has the pair of connectors 65 and 66 preliminarily connected to both ends as shown in FIG. 7 and requires soldering either of the connectors 65 and 66 to the end of the cable 64 or soldering the ends of the cable 64 directly to the control circuits after passing only the cable 64 through and along the center slots 67 and 68, thereby remarkably complicating a wiring work. Moreover, since both the ends of the cable 64 which is laid in and along the center slots 67 and 68 are fixed with the connectors 65, 66, etc. and a rotation of the cable 64 is limited in the center slots 67 and 68, the wiring device poses a problem that the cable 64 is liable to be injured and its service life is shortened due to rubbing and twisting in the center slots 67 and 68 during rotations of the rotating shafts 54 and 55.
The present invention has been achieved in view of the points described above to propose a rotary bearing device, a joint device, a wiring device for joint mechanism and a robot which are configured to facilitate wiring, improve aesthetic appearances and prolong a service life of a wiring material.
In order to solve such a problem, the present invention provides a rotary bearing device consisting of at least a rotating shaft and a bearing for holding the rotary shaft, wherein a concave groove is formed in a portion of an outer circumference of the rotating shaft along an axial direction of the rotating shaft.
As a result, the rotary bearing device allows a wiring material to be laid in the concave groove formed in the portion of the outer circumference of the rotating shaft along the axial direction, thereby making it possible to easily lay even a wiring material which has connectors connected to both ends in and along the concave groove of the rotating shaft without exposing the wiring material outside the joint mechanism. Since the rotary bearing device allows even the material which has the connectors connected to both the ends to be easily laid in and along the concave groove of the rotating shaft without being exposed outside the joint mechanism, the rotary bearing device can have an improved aesthetic appearance and prevent the wiring material from being twisted or rubbed, thereby remarkably prolonging a service life of a cable.
Furthermore, the present invention provides an joint device using a rotating shaft and a bearing for holding the rotating shaft, wherein a concave groove is formed in a portion of an outer circumference of the rotating shaft along an axial direction of the rotating shaft.
As a result, the joint device allows a wiring material to be laid in the concave groove formed in the portion of the outer circumference of the rotating shaft along the axial direction, thereby making it possible to easily lay even a wiring material which has connectors connected to both ends in and along the concave groove of the rotating shaft without exposing any wiring material outside the joint mechanism. Since the joint mechanism allows even the wiring material which has connectors connected to both ends to be easily laid in and along the concave groove of the rotating shaft without being exposed outside the joint device, the joint device can have an improved aesthetic appearance and prevent the wiring material from being twisted or rubbed, thereby remarkably prolonging a service life of a cable.
Furthermore, the present invention provides an joint device using a rotating shaft, wherein a concave groove is formed in a portion of the outer circumference of rotating shaft along an axial direction of the rotating shaft, a wiring material is laid in and along the concave groove of the rotating shaft, and the wiring material is located in the concave groove with a ring like member fitted over the outer circumference of the rotating shaft.
As a result, this joint device allows even a wiring material which has connectors connected to both ends to be easily laid in the concave groove of the rotating shaft without being exposed outside the joint device, thereby not only having an improved aesthetic appearance and being capable of remarkably prolonging a service life of a cable by preventing the wiring material from being twisted or rubbed but also being capable of preventing the wiring material from springing out of the concave groove by locating the wiring material in the concave groove with the ring like member fitted over the outer circumference of the rotating shaft to make it possible to lay the wiring material within a minimum space, prevent the wiring material from springing out of the concave groove during rotation of the rotating shaft and securely maintain stability of the wiring material.
Furthermore, the present invention provides an joint device which uses a rotating shaft and a bearing having an inner ring for supporting an outer circumference of the rotating shaft, in which a concave groove is formed in a portion of the outer circumference of the rotating shaft along an axial direction of the rotating shaft, a wiring material is laid in and along the concave groove of the rotating shaft and the wiring material is located in the concave groove with the inner ring of the bearing fitted over the outer circumference of the rotating shaft.
As a result, this joint device allows the bearing to function also as means in particular for preventing the wiring material from springing out of the concave groove of the rotating shaft, thereby making it possible to reduce the number of parts and the number of assembling steps. Moreover, the joint device allows the inner ring of the bearing which prevents the wiring material from springing out of the concave groove to be rotated together with the rotating shaft, thereby being capable of preventing a risk of the wiring material from being rubbed and injured by the inner ring during rotation of the rotating shaft and remarkably prolonging a service life of the wiring material.
Furthermore, the present invention provides an joint device using a rotating shaft and is configured by laying a wiring material having a pair of connectors connected to both ends along an axial direction of the rotating shaft, wherein a concave groove is formed in a portion of an outer circumference of the rotating shaft in the axial direction of the rotating shaft, the wiring material is laid along the concave groove of the rotating shaft in a condition where one of the connectors of the wiring material is inserted through a center hole of a ring like member and the wiring material is located in the concave groove by fitting the ring like member over the outer circumference of the rotating shaft.
As a result, this joint device allows the wiring material to be easily laid in the concave groove formed in the portion of the outer circumference of the rotating shaft along the axial direction in a condition where the connectors are preliminarily connected to both the ends of the wiring material so far as the connectors have a size which can be inserted through the center hole of the ring like member. Accordingly, the joint device makes it possible to eliminate tedious procedures of connecting the connectors to the ends of the wiring material after laying the wiring material, thereby remarkably facilitating the wiring work.
Furthermore, the present invention provides a wiring device for joint mechanism which uses a rotating shaft, a gear formed at an end of the rotating shaft and an inner ring of a bearing for supporting an outer circumference of the rotating shaft, wherein an L shaped concave groove is composed of a first concave groove formed in a portion of the outer circumference of the rotating shaft along an axial direction of the rotating shaft and a second concave groove formed in a radial shape which is connected to an end of the first concave groove and ranges from a side surface of the gear to an outer circumference of the gear, a wiring material is laid in and along the L shaped concave groove and the wiring material is located in the L shaped concave groove with the inner ring of the bearing fitted over the outer circumference of the rotating shaft.
As a result, this wiring device for joint mechanism allows the wiring material to be laid within a minimum space and allows the inner ring of the bearing which prevents the wiring material from springing out of the L shaped concave groove to be rotated together with the rotating shaft, thereby making it possible to prevent the wiring material from being rubbed and injured by the inner ring during rotation of the rotating shaft, and remarkably prolong a service life of the wiring material. Since the wiring device for joint mechanism requires only formation of the outer concave groove in the portion of the outer circumference of the rotating shaft and eliminates a necessity to use a hollow shaft having low strength as the rotating shaft, the wiring device for joint mechanism makes it possible to reserve sufficient strength for the rotating shaft and obtain a durable joint mechanism. Since the wiring material is not inserted through a center of the rotating shaft, an angle sensor or the like can be attached coaxially to an end of the rotating shaft, thereby making it possible to configure the joint mechanism compact.
Furthermore, the present invention provides a robot which uses, in an joint part of a body, a rotary bearing device according to claim 1 or claim 2, an joint device according to claim 3, claim 4, claim 5, claim 6, or claim 7, or a wiring device for joint mechanism according to claim 8 or claim 9.
As a result, this robot has a wiring material not exposed outside joints of leg members, an improved aesthetic appearance, compact joints and remarkably miniatured design.